A Design Aid for Structural Engineers
Circular Storage Tanks and Silos, Third Edition
effectively explains and demonstrates the concepts needed in the analysis and design of circular tanks. Tanks have to sustain high-quality serviceability over a long lifespan. This text covers computing the stresses in service in several chapters. It considers thermal stresses and the time-dependent stresses produced by creep and shrinkage of concrete and relaxation of prestressed steel. It also examines the effects of cracking and the means for its control. This text is universally applicable; no specific system of units is used in most solved examples. However, it is advantageous to use actual dimensions and forces on the structure in a small number of examples. These problems are set in SI units and Imperial units; the answers and the graphs related to these examples are given in the two systems.What’s New in This Edition:
This guide is an authoritative resource for the analysis and design of circular storage tanks and silos.
PART I Analysis
Introduction to the analysis of circular tanks
Scope
Basic assumptions
General methods of structural analysis
The displacement method
The force method
Flexibility and stiffness matrices
Moment distribution
Adjusted stiffness and flexibility coefficients
General
Circular walls of constant thickness
Introduction
Beam-on-elastic-foundation analogy
General solution of the differential equation of the deflection of a wall of constant thickness
Characteristic parameters
Stiffness and flexibility matrices
End-rotational stiffness and carry-over factor
Fixed-end forces
Semi-infinite beam on elastic foundation and simplified equations for long cylinders
Classification of beams on elastic foundation and circular walls as long or short
Examples
General
Circular walls of varying thickness
Introduction
Finite-difference equations
Boundary conditions and reactions
Generation of simultaneous equations
Sudden change in thickness
Examples
Flexibility and stiffness of circular walls of variable thickness
Effect of temperature
General
Design tables and examples of their use
Introduction
Description of design tables
Variables
Arbitrary edge conditions
Examples
Long cylinders
Poisson’s ratio
Beams on elastic foundations
General
Finite-element analysis
Introduction
Nodal displacements and nodal forces
Transformation of stiffness matrix
Displacement interpolations
Stress resultants
Stiffness matrix of individual element
Analysis for effect of temperature
Assemblage of stiffness matrices and load vectors
Nodal forces
Examples
Time-dependent effects
Introduction
Creep and shrinkage of concrete
Relaxation of prestressed steel
Basic equations for stress and strain distributions in a homogeneous section
Time-dependent stress and strain in a section
Normal force N and bending moment M due to prestressing
Time-dependent internal forces
Thermal stresses
Introduction
Effects of temperature variation in a cylindrical wall
Linear temperature variation through wall thickness
Thermal internal forces in deep tanks and silos
Internal forces due to shrinkage of concrete
Significance of linear analysis
Optimum design of prestressing
Introduction
Trapezoidal distribution of circumferential prestressing
Design objectives
Design of circumferential prestress distribution
Effects of cracking of concrete
Introduction
Stress and strain in a cracked section
Decompression forces
Equilibrium equations
Rectangular section analysis
Tension stiffening
Crack width
Time-dependent strain and stress in cracked sections
Influence of cracking on internal forces
Control of cracking in concrete tanks and silos
Introduction
Causes of cracking
Tensile strength of concrete
Force-induced cracking
Displacement-induced cracking
Cracking by bending: force-induced and displacement-induced
Motives for crack control
Means of controlling cracking
Minimum reinforcement to avoid yielding of reinforcement
Amount of reinforcement to limit crack width: displacement-induced cracking
Change in steel stress at cracking
Part II Design tables
Tables for analysis of circular walls of thickness varying linearly from top to bottom
Appendices:
Stiffness and fixed-end forces for circular an annular plates
Computer program CTW (cylindrical tank walls)
Computer program SOR (shells of revolution)
Index
Biography
Amin Ghali, Ph.D., is a professor emeritus in civil engineering at the University of Calgary, Canada. His books include Ghali, Neville, and Brown, Structural Analysis, 6th ed. (CRC Press/ Spon Press, 2009) and Ghali, Favre, and Elbadry, Concrete Structures: Stresses and Deformations: Analysis and Design for Serviceability, 4th ed. (CRC Press/ Spon Press, 2011). Dr. Ghali has published more than 250 papers on analysis and design of concrete structures. He has also consulted on major projects that include three offshore platforms in the North Sea; major bridges in Canada, France, and Bahrain; and the Northumberland Strait Bridge connecting Prince Edward Island and New Brunswick.
"The new edition of Circular Storage Tanks and Silos is an excellent reference book and is recommended for graduate students, practicing engineers and researchers. It would be a worthy addition to the libraries of universities and the bookshelves of practising engineers."
—Proceedings of the Institution of Civil Engineers, 2016
